Spindle cell haemangioendothelioma: Probably a benign vascular lesion not a low-grade angiosarcoma

Ten cases of spindle cell haemangioendothelioma (SCH) were analysed clinicopathologically, including an immunohistochemical survey of seven cases and ultrastructural observations on one. There were seven females and three males, ranging from 16 to 76 years of age. All but one lesion developed on the extremities, predominantly on the hands and feet. Six of the ten patients presented multiple nodules or papules which gradually increased in size and number over a long duration. Among them, four patients had undergone operations twice or more, but no metastatic foci were recognized. Histologically, the lesions were composed of dilated vascular spaces and a proliferation of bland-appearing spindle cells and interspersed epithelioid endothelial cells. Ultrastructural and immunohistochemical studies demonstrated that the spindle cells were mainly made up of fibroblastic cells admixed with pericyte-like cells and macrophages. Smooth muscle cells and primitive mesenchymal cells were also present. The clinical and microscopic features suggest that SCH may be a benign vasoformative lesion of a heterochronological multicentric origin.

Crystal structure of ribonuclease T1 complexed with adenosine 2'-monophosphate at 1.8-A resolution

Ribonuclease T1 was purified from an Escherichia coli overproducing strain and co-crystallized with adenosine 2'-monophosphate (2'-AMP) by microdialysis against 50% (v/v) 2-methyl-2,4-pentanediol in 20 mM sodium acetate, 2 mM calcium acetate, pH 4.2. The crystals have orthorhombic space group P2(1)2(1)2(1), with cell dimensions a = 48.93(1), b = 46.57(4), c = 41.04(2) A; Z = 4 and V = 93520 A3. The crystal structure was determined on the basis of the isomorphous structure of uncomplexed RNase T1 (Martinez-Oyanedel et al. (1991) submitted for publication) and refined by least squares methods using stereochemical restraints. The refinement was based on Fhkl of 7,445 reflections with Fo greater than or equal to 1 sigma (Fo) in the resolution range of 10-1.8 A, and converged at a crystallographic R factor of 0.149. The phosphate group of 2'-AMP is tightly hydrogen-bonded to the side chains of the active site residues Tyr38, His40, Glu58, Arg77, and His92, comparable with vanadate binding in the respective complex (Kostrewa, D., Choe, H.-W., Heinemann, U., and Saenger, W. (1989) Biochemistry 28, 7592-7600) and different from the complex with guanosine 2'-monophosphate (Arni, R., Heinemann, U., Tokuoka, R., and Saenger, W. (1988) J. Biol. Chem. 263, 15358-15368) where the phosphate does not interact with Arg77 and His92. The adenosine moiety is not located in the guanosine recognition site but stacked on Gly74 carbonyl and His92 imidazole, which serve as a subsite, as shown previously (Lenz, A., Cordes, F., Heinemann, U., and Saenger, W. (1991) J. Biol. Chem. 266, 7661-7667); in addition, there are hydrogen bonds adenine N6H . . . O Gly74 (minor component of three-center hydrogen bond) and adenosine O5' . . . O delta Asn36. These binding interactions readily explain why RNase T1 has some affinity for 2'-AMP. The molecular structure of RNase T1 is only marginally affected by 2'-AMP binding. Its "empty" guanosine-binding site features a flipped Asn43-Asn44 peptide bond and the side chains of Tyr45, Glu46 adopt conformations typical for RNase T1 not involved in guanosine binding. The side chains of amino acids Leu26, Ser35, Asp49, Val78 are disordered. The disorder of Val78 is of interest since this amino acid is located in a hydrophobic cavity, and the disorder appears to be correlated with an "empty" guanosine-binding site. The two Asp15 carboxylate oxygens and six water molecules coordinate a Ca2+ ion 8-fold in the form of a square antiprism.

[Cloning and sequencing of a highly repeated DNA fragment of rabbit]

We obtained highly repeated DNA fragments from a rabbit by using restriction endonuclease HindIII digestion of chromosomal DNA; the smallest highly repeated DNA fragment was cloned into vector plasmid pUC12. We used the recombinant plasmid to transform E. coli JM101, selected and identified the positive clone by DNA probe in situ hybridization as well as Southern blotting. We obtained a recombinant clone [termed pRAb (Hind III)-1] which contains the highly repeated DNA fragment [termed RAb (Hind III)-1]. The complete nucleotide sequence of the 345bp RAb (Hind III)-1 fragment was determined by the dideoxynucleotide termination sequencing method. We analyzed the characteristics of the structure of the sequence with a microcomputer, and the results suggested that the RAb (Hind III)-1 sequence is quite different from alphoid DNA of primates.

[Studies and comparisons on chemical components of essential oils from Clematis hexapetala Pall. and Inula nervosa Wall]

Chemical components of the essential oils from clematis hexapetala and Inula nervosa were analyzed by using GC-MS-DS. The result shows that the major components of the essential oil from Inula nervosa are thymol and thymol isobutyrate, while the major components of the essential oil from Clematis hexapetala are palmitic acid and 3-hydroxy-4-methoxyl benzaldehyde.

Clear cell chondrosarcoma. A case report with topographic analysis

A case of clear cell chondrosarcoma located in the right proximal end of the femur is presented. Radiologically, the tumor appeared as a large osteolytic lesion with mottled calcification resembling chondroblastoma. Histologically, the greater portion was made up of tumor cells with abundant clear cytoplasm and usually distinct boundaries, associated with areas of conventional chondrosarcoma. The proportion of the clear cell areas was about 60%, and they were mainly distributed along the tumor periphery. Moreover, myxoid chondrosarcoma-like areas, a feature not previously mentioned in clear cell chondrosarcoma, were observed, occupying about 10% of the tumor area.

Dermatofibrosarcoma protuberans with fibrosarcomatous areas. A clinicopathologic study of nine cases and a comparison with allied tumors

Nine cases of dermatofibrosarcoma protuberans with fibrosarcomatous areas (DFSP with FS) were analyzed clinicopathologically, and the findings compared with allied tumors comprising 43 cases of ordinary DFSP, ten of superficial fibrosarcoma (SFS), and 11 of storiform variant of malignant fibrous histiocytoma (SV MFH). All but one case of DFSP with FS developed on the trunk of the body. Eight of the nine patients (89%) had one recurrence with a shorter prerecurrent interval than that of the ordinary DFSP, and a hipbone metastasis was identified in one patient. These findings reflect the unfavorable course, in contrast to the ordinary DFSP. Microscopically, the FS areas were presented either in the initial lesion (five cases) or in the recurrent one (four cases), areas showing cellularity, mitotic figures, and cytologic anaplasia that exceeded those in the DFSP areas. Dermatofibrosarcoma protuberans with FS and allied categories such as SFS and SV MFH shared various clinical and histologic features but there was a diversity in the prognosis relative to the grade of malignancy. The relationship between DFSP with FS and the allied tumors was given attention.

Ventricles as a major site of atrial natriuretic factor synthesis and release in cardiomyopathic hamsters with heart failure

The aim of the present study was to correlate in cardiomyopathic hamsters with congestive heart failure the levels of atrial and ventricular atrial natriuretic factor (ANF) messenger RNA (mRNA) with immunoreactive ANF (IR-ANF) plasma levels and the relative amount of IR-ANF released by the whole heart versus isolated ventricles in the Langendorff preparation. High-performance liquid chromatography analysis of the forms of ANF present in plasma and in the Langendorff effluent of whole heart versus isolated ventricles was also performed. As previously found for cardiac IR-ANF, the levels of ANF mRNA decreased gradually in atria and increased in an analogous fashion in ventricles with the severity of congestive heart failure. Plasma IR-ANF levels (C-terminal) were more elevated in moderate than in severe congestive heart failure, as were the IR-ANF levels in the Langendorff effluent of the whole heart. On the contrary, the effluent of isolated ventricles from animals in severe heart failure yielded more IR-ANF than that from hamsters in moderate heart failure. Thus, while the isolated ventricles from controls contributed 35.8% of IR-ANF released by the whole heart, ventricles from hamsters in moderate heart failure contributed 17.5%, and those from hamsters in severe heart failure contributed 73.9%. These results indicate that atrial cardiocytes contribute more IR-ANF than their ventricular counterpart in moderate heart failure and that ventricles are a major source of plasma IR-ANF in severe heart failure. Analysis of IR-ANF from plasma and the Langendorff effluent from whole hearts and isolated ventricles revealed that the ventricles are the major source of the propeptide (and of its cleaved products) found in the circulation of cardiomyopathic hamsters. These results suggest that ANF synthesis and secretion do not increase conjointly in atria but do increase in ventricles during congestive heart failure.

Atrial natriuretic factor in the impulse-conduction system of rat cardiac ventricles

A complex network of atrial natriuretic factor-producing cells has been delineated by biochemical and morphological techniques in the rat ventricular myocardium. The chordae tendineae spuriae (CTS; false tendons) contain ANF mRNA and the ANF propeptide (Asn 1-Tyr 126) as assessed by Northern blot analysis, high-pressure liquid chromatography and immunohisto- and -cytochemistry, using three different affinity-purified antibodies: monoclonal and polyclonal antibodies against C-terminal ANF (Arg 101-Tyr 126) and polyclonal antibodies against N-terminal ANF (Asp 11-Ala 37). Two types of cells harboring ANF-containing secretory granules constitute the CTS: the majority (Purkinje type I) have ultrastructural similarities with both atrial and classical Purkinje fibers. Purkinje type-II fibers resemble working ventricular cardiocytes. Both cell types harbor a large paranuclear Golgi complex. The subendocardial Purkinje network is also made up of these two cell types. In this location, Purkinje type-I fibers form cable-like structures while Purkinje type-II fibers are either located beneath the former or abut directly on the endocardium. The latter are not separated from adjacent working ventricular cardiocytes by connective tissue septa. Coronary arteries and arterioles, as in birds, are surrounded by a cushion of Purkinje type-II fibers which blend with the surrounding myocardium. These results indicate that, in the rat, the entire intraventricular conduction system is constituted of endocrine cells producing ANF.

Atrial natriuretic factor (ANF) gene expression in the Brattleboro rat

Atrial natriuretic factor (ANF) is a 28-amino acid peptide hormone of cardiac origin. It has natriuretic, diuretic and vasorelaxant properties and inhibits several cardiovascular modulators. Because of the possible effects of arginine vasopressin (AVP) on ANF secretion, we have investigated ANF gene expression in Brattleboro rats which are genetically deficient in AVP. Our results indicate that cardiac ANF mRNA and ANF content are higher in Brattleboro rats compared to Long-Evans controls, whereas the plasma levels are similar in both groups. Typical secretory granules containing immunoreactive ANF are present in ventricular cardiocytes of Brattleboro but not of Long-Evans rats. These data suggest that ANF release may be uncoupled from its synthesis in the absence of AVP.

Immunoreactive atrial natriuretic factor is present in both atria and ventricles

A comparative study has been made of the amount and form of immunoreactive atrial natriuretic factor (ANF) present in atria versus ventricles in situ and in cultures of atrial and ventricular cardiocytes in rats of various ages: foetus (-2 days of age), newborn (3 days of age), 10 days, 35 days and 70 days old. It was first established that ANF is present in the circulation at all ages investigated, the highest levels being found in the foetus. The atrial content of ANF increased gradually with time and was always in the microgram range. In ventricles, where it was in the nanogram range, total ANF increased with age. More ANF was found in the right than in the left atrium at all ages except in the foetus where the reverse was true. In ventricles, ANF was distributed equally between right ventricle, left ventricle and septum in the foetus, the newborn and in the adult. At 10 days and 35 days, ANF was unequally distributed: (right ventricle greater than septum greater than left ventricle). In cultured atrial cardiocytes, ANF was more abundant than in cultured ventricular cardiocytes at all ages and the amount decreased with the age of the donor animals. Atrial cardiocytes secreted more ANF than did ventricular cardiocytes at all ages investigated, the amount secreted generally decreasing with the age of the donor animals. The secretory activity of atrial cardiocytes per hour was also higher than that of their ventricular counterparts; over this time period, both types of cells secreted more ANF in the presence of serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac and plasma atrial natriuretic factor in experimental congestive heart failure

The cardiac and plasma levels of immunoreactive (IR-) atrial natriuretic factor (ANF) in cardiomyopathic hamsters with moderate and severe congestive heart failure were measured, compared with those of controls, and correlated by HPLC analysis of IR-ANF in atria, ventricles, and plasma and with the ultrastructure of atrial and ventricular cells. Congestive heart failure in the hamster produced a significant increase in plasma IR-ANF, a significant decrease in atrial IR-ANF, and a marked increase in ventricular IR-ANF. The HPLC pattern of IR-ANF was of the high mol wt type in atria and ventricles of control and cardiomyopathic animals. High mol wt forms of ANF appeared in the plasma of animals with severe congestive heart failure, but not in controls. Severe congestive heart failure produced a tremendous increase in the size of the Golgi complex, with a decrease in the number and size of secretory granules in atrial cardiocytes. Ventricular cardiocytes also showed a less marked increase in the size of the Golgi complex. Secretory-like granules indistinguishable from lysosomes were present in about 1% of ventricular cardiocytes of control hamsters; in hamsters with severe congestive heart failure, secretory granules, identical to those of atrial cardiocytes, were present in greater number in about 20% of ventricular cardiocytes. Immunocytochemistry (immunogold technique) revealed that secretory granules containing IR-ANF are not present in control ventricular cardiocytes but are localized in relatively large number in about 20% of ventricular cardiocytes in hamsters with severe congestive heart failure. These results suggest that the increased IR-ANF levels (including the high mol wt forms) in animals with congestive heart failure may come from hypersecretion of both atrial and ventricular cardiocytes.

Orientation and expression of the cloned hemolysin gene of Pseudomonas aeruginosa

The structural gene for Pseudomonas aeruginosa hemolysin, carried on recombinant plasmid pSL2 and cloned in Escherichia coli, was analyzed by insertional and deletional mutagenesis. Expression of the hemolysin was blocked by insertion of transposon Tn5 into different locations. Two of the mutants allowed detectable synthesis of truncated hemolysin polypeptides of two different sizes and thus defined the structural gene. The location of the hemolysin gene in the recombinant plasmid, and the direction of transcription, were further established by nuclease BAL 31 digestion, and by construction of gene fusions between hemolysin and beta-galactosidase. Evidently, the tet promoter contributed to the majority of the expression of cloned hemolysin gene, but the Pseudomonas promoter was present in the cloned DNA and was functional in E. coli since inactivation of the tet promoter either by Tn5 insertion or by deletion decreased synthesis of the 80-kDal hemolysin but did not fully abolish it.